Such a safety ski binding is broadly known from Swiss Pat. No. 460610, published Sept. 30, 1968. In this known binding, the plate is arranged on the ski for lateral pivoting and is equipped at its rear with an automatic heel engaging means having forward release capability. Upon release of the locking device which in front cooperates with the boot plate, the plate can swivel laterally and upon forward release of the heel means the ski boot is released from the plate. A disadvantage of this known construction is, however, that during a torsion stress, the ski boot does not come free from the ski or from the plate. Instead, the ski boot is held in the pivoted position of the plate by the locking device.
In a further known device according to German OS No. 2221105, published Nov. 23, 1972, the ski boot is released from the ski during a torsion stress but it remains attached to the plate. This is a disadvantage because the ski boot during walking remains encumbered by the plate. Moreover, a subsequent entry into the holding devices provided on the ski is difficult with the additional plate because in such case the rotary plate must also be brought into engagement with the pivot pin.
A similar device is described in German OS No. 2051758, published Apr. 27, 1972. In this construction, the rear heel support device has a bearing block which is fixedly connected to the sole plate and serves as a guide part. The bearing block is equipped with a rearwardly sloped, steeply rising guide curve, in which the sole holder is guided by means of a slip joint. The holder is formed as a part of a control lever, which is a part of a control lever pair, in which the components are positioned angularly with respect to one another. The control lever which is positioned substantially vertically is held down by a lock lever, which releases the heel holder by swiveling. The bearing block also carries a locking member which is held by a locking device arranged behind the heel support device on the ski. The locking device consists substantially of a pivotable locking lever, which holds on one side the locking roller and on the other side is supported on a flexible locking piston. The sole plate is here also pivotable about an axis of rotation which is arranged substantially in the center area of the plate. If excessive forces act onto the ski boot, the sole plate slides out of the pivot pin, so that the plate is released along with the boot from the ski. The disadvantages of this device consist both in the boot being released with the sole plate from the ski and in that for voluntary and involuntary release special devices have to be provided.
In another known device according to German OS No. 1578860, published Dec. 10, 1970, two plates are provided, of which the one effects only the vertical release and the other the rotary release. After the release, the plate which is anchored in the ski remains connected to the ski, the locking mechanism for the second plate being secured on this plate. This construction has the disadvantage that, in order to obtain different release actions, two plates must be provided, which not only increases expense and weight and makes handling more difficult, but due to the excessively elevated position adversely affects the skiing.
For anchoring the known plate bindings, aside from the already mentioned references, still others are known which solve this problem in still further ways. For example, in German OS No. 2157791 published June 15, 1972, a locking part which engages the guideway is hinged to the front end of the release plate.
Further devices are known which have pistons with mushroom-shaped thrust pieces. Such as described for example in Swiss Pat. No. 443,089, published Jan. 3, 1968, or in Austrian Pat. No. 303,578, corresponds to U.S. Pat. No. 3,489,424. These mushroom-shaped connecting members have, however, the disadvantage that during the release the entire force is concentrated on a relatively small surface which causes considerable frictional resistance. Similar difficulties exist in an embodiment according to Swiss Pat. No. 300,633, published Oct. 16, 1954, wherein the frictional forces are created not only on the mushroom-shaped member but also on a conically constructed end piece.
In a known safety ski binding according to Austrian Pat. No. 270,468, published July 15, 1968, the jaw has a guide surface which engages a stop which is fixedly connected to the ski or the housing, a spring or the like held on the ski or on the housing being hinged to one arm of the jaw. While this construction has nothing in common with a safety ski binding as such, in which the ski boot is secured on a plate, there is in this reference some suggestion for holding of the sole.
Finally, references are known which have a ski brake cooperating with the holding device. Such devices are for example known from Austrian Pat. No. 308,610, published Oct. 15, 1972 and No. 310,631, published Jan. 15, 1973, and German OS No. 2360338, published June 6, 1974. All these mentioned constructions have in common that they are held by the heel holder and upon release of the same free the ski brake.